According to published reports, a substantial percentage of raw chicken purchased in stores has been found to be infected with Salmonella bacteria. Salmonella is pathogenic for man and can produce a variety of uncomfortable symptoms ranging from mild to life-threatening.
Salmonella infected chicken (or other poultry) has not generally been regarded as a serious health problem in the past since the Salmonella bacteria is destroyed by heat pasteurization in the normal process of cooking the chicken. When cooking a chicken in a microwave oven, however, the chicken itself receives enough heat energy to achieve pasteurization, but the cooking juices sometimes do not. This occurs because cooking vessels may be used in which the cooking juices are collected in a chamber protected from microwaves, in order to save energy and to protect the juices from boiling or smoking. Such cooking vessels may prevent pasteurization of the juices and, so, be dangerous to health.
Various microwave cooking vessels, useful for this saving of energy, have been devised. These include, for example, those found in Krajewski U.S. Pat. No. 3,230,864, Levinson U.S. Pat. No. 3,985,990, and Eke U.S. Pat. No. 4,653,461.
In the Levinson patent a shielded chamber for the collection of liquid by-products is integral to the vessel and results in more efficient functioning. Liquid by-products not so shielded would absorb relatively large amounts of microwave energy, resulting in extended cooking time and, ultimately, in the production of undesirable quantities of steam or smoke, or both.
The Krajewski patent discloses a cooking vessel in which the food is supported on an apertured, electrically conductive, partially insulated cover elevated above a container intended to capture liquid by-products. The Eke patent shows a trivet insulated from the oven turntable; it also provides a collection chamber.
The disclosures of these patents are directed to saving energy and/or prevention of smoke without addressing the problem of destroying Salmonella bacteria or other organisms harmful to human health. Yet, underheating as well as overheating of liquid by-products can be a problem in microwave cooking, particularly in the cooking of poultry.
My invention is aimed at addressing the problem of destroying Salmonella bacteria (or other bacteria which can be destroyed by pasteurization) while providing cooking efficiency and utility substantially equivalent to that which has been disclosed in the prior art.